Hypoplastic Right Heart Syndrome – The Half-Heart Syndrome
Photo courtesy of Unsplash
By Nameera Pervez Temkar
As I scrolled on Instagram, I came across a reel. A doctor had changed a baby’s life on the other side of the world. Nadine was diagnosed with Hypoplastic Right Heart Syndrome (HRHS), one of the two half-heart syndromes, the other being Hypoplastic Left Heart Syndrome (HLHS), when she was still in her mother’s womb. The doctors in UAE had said there was nothing they could do, but her mother, a doctor herself, searched for answers.
Nadine underwent fetal intervention, just an idea in a research paper years ago. Today, Nadine is a happy child with a full heart – a heart warrior.
What is HRHS?
Dr. Doaa was at a doctor’s (obstetrician’s) appointment when her doctor gave her the news. Her unborn child had a rare condition – Hypoplastic Right Heart Syndrome (HRHS).
Hypoplastic Right Heart Syndrome is present from birth (congenital) and is rarer than its counterpart, Hypoplastic Left Heart Syndrome. HRHS occurs when the right side of the baby’s heart is underdeveloped, which leads to improper blood flow.
Blood rich in carbon dioxide from the rest of the body comes to the right side of the heart and is pushed into the lungs to get oxygenated. When the right side of the heart doesn’t develop properly, the baby turns blue due to a lack of oxygen, a condition known as cyanosis. Hence, HRHS is also called a cyanotic congenital condition.
When and how is HRHS diagnosed?
HRHS, like HLHS, is usually diagnosed during an ultrasound checkup. In cases where you haven’t had a single ultrasound during your pregnancy, you wouldn’t know of the diagnosis until after birth.
During monthly or weekly checkups, your doctor checks for any abnormality, whether of the internal organs or the external body parts. Your doctor may refer you to a specialist, like a pediatric cardiologist, if anything is suspected.
What happens in HRHS?
Hypoplastic Right Heart Syndrome affects the right side of the heart and, more specifically, leads to its underdevelopment.
The heart consists of four chambers – two atriums and two ventricles. The tricuspid valve is between the right atrium and ventricle, and the pulmonary valve is between the right ventricle and the pulmonary artery. In HRHS, a child can suffer from different defects.
The tricuspid and pulmonary valves may be blocked, absent, unopened, or too small. There may also be defects in the right ventricle and the pulmonary artery.
In congenital diseases like HRHS and HLHS, these defects may accompany other congenital defects such as narrowing of the aorta (coarctation of the aorta), non-closure of foramen ovale (patent foramen ovale), non-closure of ductus arteriosus (patent ductus arteriosus), two superior vena cava (bilateral superior vena cava) and other Congenital heart defects(CHDs).
Treatment Options
Your doctor may start discussing your child’s treatment options before birth, which may help you prepare for the days after your child is born. There are two kinds of medical treatments available – Surgical treatments after your baby is born and fetal intervention before your baby is born. Not all countries perform fetal interventions; your doctor may be unaware of this option.
Surgical treatments
Surgical treatments for both HRHS and HLHS involve three surgeries. These three surgeries are staged reconstruction heart surgeries because they are done within specific periods. However, your child may not need a certain surgery and hence may skip one.
Blalock-Taussig Shunt
This procedure is done within the first few weeks of the baby’s life and usually within the first week. The Blalock–Taussig shunt is performed to increase the blood flow to the lungs. Babies suffering from HRHS have a problem with blood reaching the lungs for oxygenation. Thus the surgeon aims to connect the subclavian artery to the pulmonary artery to help blood flow to the lungs.
Glenn Procedure
The Glenn procedure is done between 4- 6 months of age. This surgery aims to reduce the amount of blood flow to the small right atrium. The surgeon connects the superior vena cava (the artery bringing blood to the right atrium from the upper body) to the pulmonary artery (the vessel which carries blood to the lungs).
Fontan Procedure
The 3rd and last surgery among the three is usually done between 2-4 years of age. Like the Glenn, in the Fontan procedure, the surgeon connects the inferior vena cava, bringing blood from the body's lower part and the pulmonary artery. After this surgery, the heart does not mix oxygen-rich and oxygen-poor blood.
Fetal intervention
Fetal intervention is a relatively newer procedure. As the name suggests, this procedure is performed on a fetus and for other organ defects.
Nadine underwent fetal intervention at UH rainbow hospital, where the team opened her pulmonary valve, which was closed due to HRHS. The closed valve prevented blood flow to the lungs and stopped the growth of the right side of her heart.
The fetal intervention performed in the case of HRHS is called fetal pulmonary valvuloplasty. This procedure is not an open surgery and is done with the help of an ultrasound. A needle is passed through the mother’s abdomen and enters the baby’s chest. A balloon is then passed into the baby’s body and inflated. Perforation of the pulmonary valve and/or dilation with a balloon catheter marks the success of this surgery.
However, as in the case of Nadine, this valve may close during birth, and your child may require open-heart surgery to open this connection again.
Fetal interventions aren't without risks, as your baby may end up dying in the womb. Not all babies are candidates for fetal interventions, and a doctor may ask you for an ultrasound picture to confirm if your baby can undergo this procedure.
What happens after your baby is born with HRHS?
Babies with HRHS can be delivered vaginally, and though the BT shunt is performed in the first few weeks of the baby’s life, a few steps are taken before the baby can undergo this procedure.
After birth, the baby is given prostaglandin (PGE), a medication that helps to keep the patent ductus arteriosus open, which helps in blood flow to the lungs. A surgeon may also perform a balloon atrial septostomy to make a larger hole between the two atria.
After the BT shunt, your baby may have feeding difficulties and need to be admitted to the NICU or the PICU. Children whose hearts become weak may require a heart transplant.
An HRHS diagnosis can be really scary.
It is a rare disease, and I hadn’t heard of it before I came across that reel.
If you are a parent with a child diagnosed with HRHS, reaching out to other parents who also have children diagnosed with HRHS may be helpful for you and them.
Facebook groups may also be a valuable resource for finding good doctors and hospitals for the baby’s treatment before and after delivery.
In my quest to find more families affected by my HRHS, I ended up joining a few groups, and here’s what I noticed:
Children diagnosed with HRHS are doing great
Parents ask questions in groups to know the best doctors/hospitals.
Other parents are willing to answer questions from parents whose child has been recently diagnosed.
HRHS is a scary diagnosis, and navigating it alone may be challenging. If your doctor cannot answer your questions, try contacting online support groups for more insight from those who were once where you are now.
About the Author
Nameera Pervez Temkar is a Freelance Writer. You can connect with her at her website: https://nameerapervez.com/
